Novel interpolymers useful as thickening agents

ABSTRACT

An interpolymer composition comprising:   Wherein Y represents -OH and O-R1 and Y and R2 together represent a single bond of an imide ring. X represents either OR -O-. R1 represents the same or different hydrocarbon radicals containing from about C6 to about C36 carbon atoms selected from the group consisting of normal chain alkyl, branched chain alkyl, cycloalkyl and alkylaryl radicals. R2 represents H or the same or different hydrocarbon radicals containing from about C1 to about C30 carbon atoms selected from the group consisting of normal chain alkyl, branched chain alkyl, cycloalkyl, and alkylaryl radicals wherein the sum total of carbon atoms represented by R1 and R2 is not greater than C36 (when X O, or an imide nitrogen,R2 does not exist). R3 represents either hydrogen, methyl, ethyl or phenyl. R4 represents either hydrogen or methyl, which compounds are particularly useful as thickening agents for solutions of high ionic strength.

United States Patent 4 1 84,777

Field et al. [451 Aug. 15, 1972 [5 1 NOVEL INTERPOLYMERS USEFUL AS UNITI UNIT 11 THICKENING AGENTS I'IIM FR;

CCH CH-CH 3Cllg ll- CH [72] Inventors: Nathan D. Field, 2736 LibertySt., I a

Allentown, Pa. 18104; Earl P. Wil- If 0:0 J liams, 803 Applegate Ave.,Pen Argyl, Pa. 18072 R1 Filed: March 20, 1970 Wherem Y represents --OHand O-R and [21] App]. No.: 21,486 R1 -x [52] US. Cl. ..260/78.5 T,71/7, 167/87, \R2 7 7 167/91, 260/29 1 R, 260,292 R, Y and R togetherrepresent a single bond of an 260/29.6 RB, 260/30.2, 260/30.6 R,260/32.6 N, 260/33.4 PO, 260/78 UA X represents either 511 int. Cl...c0sr 27/12 -I I [58] Field of Search ..260/78.5 T or 0 I R representsthe same or different hydrocarbon [56] References Cited radicalscontaining from about C to about C UNITED STATES PATENTS carbonattlumshselected from thehgroup consisting lkyl, branc ed chain alkyl,2,977,334 3/1961 Zopfet al. ..260/27 8 z f l yco yan yary ra 10 s. g gqet R represents H or the same or different hydrocar- 6 12 1954 9 bonradicals containing from about C, to about f i' "260/78 C carbon atomsselected from the group consist- 3,506,625 4/ 1970 Patmkin et al..260/78.5 ing of normal chain alkyl branched chain alkyl,

cycloalkyl, and alkylaryl radicals wherein the sum total of carbon atomsrepresented by R and R is not reater than C when X=O, or an imid PrimaryExaminer-Joseph L. Schofer g 36 e nitrogen,R does not exist).Ass'stamExammer Jh" i In R represents either hydrogen, methyl, ethyl orAttorney-Samson B. Leavitt, Walter C. Kehm and phenyL Fritschler Rrepresents either hydrogen or methyl, which compounds are particularlyuseful as thickening [57] ABSTRACT agents for solutions of high ionicstrength.

An interpolymer composition comprising: 7 Claims No Drawings NOVELINTERPOLYMERS USEFUL AS THICKENING AGENTS The instant invention isdirected to novel interpolymer compositions. In particular, the instantinvention is directed to interpolymer compositions which contain amoderate amount of a long chain component in the amide, imide or esterportion of a derivative of a copolymer of maleic anhydride and styreneor maleic anhydride and a lower olefin.

The instant novel compounds have been found to be very useful inthickening solutions of high ionic strength, including concentrated saltsolutions as well as bases and acids where most conventionalwater-soluble polymers have little effect or are insoluble. For example,the instant interpolymers are very effective in thickening percentdiammonium phosphate solution, which is used in fire-fighting andpercent tetrapotassium pyrophosphate which is used in detergentcompositions and 5 percent sodium. bromate which is used in permanentwave formulations. Moreover, the instant interpolymers are veryeffective forthickening concentrated ammonia as well as for thickeningother strong alkali solutions such as sodium hydroxide, sodiumcarbonate, trisodium phosphate and sodium silicate. The thickenedammonia solutions are useful as agricultural fertilizers and thethickened strongly alkaline solutions are useful as heavy duty cleaners,paint removers, oven cleaners, etc. Moreover, the instant compounds maybe used to thicken water and rubber latices as well as nonaqueoussolutions or mixtures of nonaqueous and aqueous solutions such asglycerine, ethylene glycol, alcohols, methyl ethyl ketone, acetone,dimethyl formamide, dioxane as well as water solutions of the above. Theinstant compounds are also useful as gelling agents in cosmeticformulations such as shampoos, hand lotions, shaving creams, etc. Theabove solutions and dispersions have good stability upon storage, infact some of them have even exhibited increased viscosity values uponstorage.

A primary object of the instant invention is to provide novelinterpolymer compounds comprising substantially equimolar quantities ofmaleic anhydride and a vinyl monomer having the formula:

wherein structural Unit 1 represents about 94 to 99.5 mole percent andstructural Unit I] represents from about 6 to about 0.5 mole percent ofthe interpolymer. It is to be noted that preferably structural Unit 1represents about to 99 mole percent and structural Unit ll representsabout 1 to 5 mole percent, and wherein Y represents -OH and O-R, and

Y and R together represent a single bond of an imide ring. X representseither R represents the same or different hydrocarbon radicalscontaining from about C to about C carbon atoms selected from the: groupconsisting of normal chain alkyl, branched chain alkyl, cycloalkyl an?alky s lra ca s.

R represents either hydrogen, methyl, ethyl or phen- R represents eitherhydrogen or methyl.

The molecular weight of the polymers of the instant invention may beconveniently defined by the specific viscosity of the precursorcopolymer. That is to say, that the molecular weight of the subjectinterpolymers may conveniently be defined by the specific viscosity ofthe copolymer wherein Unit I and Unit II are both totally anhydrideunits prior to the amidation or esterification of Unit II. In suchinstances, 1.00 gram of the anhydride copolymer per 100 ml. of acetonesolution should have a specific viscosity at 25 C. in the range of fromabout 0.1 to 25.0. Preferably said anhydride copolymers should have a.specific viscosity at 25 in acetone from about 0.2 to about 20.0.

The novel compounds of the instant invention may be prepared byconventional known methods. For example, by interpolymerizing maleicanhydride and a vinyl monomer using approximately 1 mole of maleicanhydride per mole of vinyl monomer. A small molar excess of the vinylmonomer mixture (5 to 10 percent) above that of the maleic anhydride maybe advantageous for ensuring complete conversion of the maleicanhydride.

The polymerization may be carried out conveniently by preparing asolvent solution of the monomers and adding a catalytic amount(preferably from 0.01 to 1.0

percent), of an organic free-radical-generating initiator. Then theresulting solution is mixed thoroughly and heated sufficiently so thatthe polymerization reaction takes place. At the completion of thepolymerization reaction the precipitated interpolymer is isolated by anysuitable means, such as by filtration, washed with fresh solvent andvacuum dried. Moreover, the polymerization may also be conducted byadding a solution of the vinyl monomer to a solution of initiator,maleic anhydride and solvent.

The amount of solvent is not critical and such solvents as benzene,toluene, xylene, acetone, methyl ethyl ketone, and methylene chloride,and the like may be used. However, benzene is considered the mostsuitable from the standpoint of product isolation and obtaining highmolecular weights.

Among the organic free-radical-generating initiators that may bementioned are azobisisobutyronitrile, benzoyl peroxide, lauroylperoxide, caprylyl peroxide, acetyl peroxide, acetylbenzoyl peroxide,di-tert-butyl peroxide or dimethyl azoisobutyrate and the like. Mixturesof such catalysts are also suitable in the process of making theinterpolymersof the invention. Radiation polymerization can be used,too, e.g., such high energy radiation sources as ultra violet light,X-rays, 'y-rays, neutrons and the like can be used to initiatepolymerization.

The polymerization may be carried out at a temperature within the rangeof to 150, preferred temperatures lie for the most part in the rangefrom 40 to 100 C., particularly about 60 to 80 C.

Other techniques for the polymerization of maleic anhydrides with vinylmonomers are set forth in US. Pat. No. 2,378,629, which is incorporatedherein by reference.

Subsequent to the preparation of the precursor copolymer, said copolymermay then be reacted with a monoamino primary or secondary aminecontaining about six to 36 carbon atoms in molar amounts of 0.5 to about6 percent of the total anhydride content. Conditions for the formationof such amides are well known in the art and are set forth in US. Pat.No. 2,456,177, which is incorporated herein be reference. In general,such amidation requires the reaction of the copolymer precursor in asuitable solvent with an amine as defined above for a period of timefrom about 10 to 30 hours at a temperature from about to about 35 C.Subsequent to such reaction, the resultant interpolymer may be separatedby filtration or other techniques, washed with fresh solvents and dried.Exemplary of the amines which are suitable for use in connection withthe present invention are the following:

hexyl amine heptyl amine octyl amine nonyl amine decyl amine hendecylamine dodecyl amine tetradecyl amine hexadecyl amine octadecyl amineoleyl amine stearyl amine octadecadienylarnine 2-aminooctane tertiarynonylarnine coconut fatty amine soya fatty amine tallow fatty aminehydrogenated tallow fatty amine tall oil amine rosin amine cyclohexylamine benzylamine di-n-propylamine di-iso-propylamine dibutyl aminediamylamine didodecylamine dioctadecylamine tridecylamine2-ethylhexylamine di-(2-ethylhexyl) amine N-methyl dodecylarnine N-ethyltetradecylamine iso-decylamine In addition to the above specific amines,mixtures thereof in any proportion may be used.

The partial esters of the subject interpolymers may be prepared byreaction of the precursor anhydride copolymer with a monohydrichydrophobic alcohol containing from about 6 to about 36 carbon atoms inmolar amounts of from about 0.5 to about 6 percent of the totalanhydride content. Such esterification procedures are well known in theart and conditions therefor are set forth in US. Pat. No. 2,938,887,which is incorporated herein by reference. In general, the partialesterification reaction requires the mixing of the precursor copolymerin solution with an alcohol as defined above for an extended period oftime at a temperature from about 10 to 200, and preferably from 20 to C.Exemplary of the alcohols which may be employed in connection with theinstant invention are:

N-hexanol n-heptanol n-octanol n-nonanol n-decanol n-dodecanoln-tetradecanol n-hexadecanol n-octadecanol oleyl alcohol branchedchained alcohols such as sec-octanol,

pentamethyloctanol tetramethylnonanol diethyloctanol In addition to theabove alcohols, those alcohols which are prepared by the catalyticreaction of an olefin such as tripropylene, tetrapropylene,pentapropylene and the like with carbon monoxide and hydrogen to form analdehyde followed by the catalytic reduction of such aldehyde to analcohol may also be employed. The above-noted process is known as theoxo process. Furthermore, alcohols such as cyclohexanol, a-terpineol,cholesterol, benzyl alcohol, B-phenylethyl alcohol, cinnamyl alcohol,citronellol and the like, as well as mixtures of any of the above, mayalso be employed. Furthermore, commercially available mixtures such asLorol 5 which contains a mixture of C to C alcohols may be used.

The partial imide of the subject interpolymers may be prepared byconverting all or part of the partial amides formed above by followingprocedures which are well known in the art. Such procedures are setforth in detail in U.S. Pat. No. 2,313,565, and US. Pat. No. 3,053,814,both of which are incorporated herein by reference. In general, thepartial imide may be formed by heating the corresponding amide for anextended period of time at a temperature from about 170 to 200 C.

The anhydride interpolymers of this invention may be converted byhydrolysis, neutralization, esterification and the like to compoundshaving the following structural units:

wherein X, Y, R,, R R and R and the mole percent-' ages of Unit I andUnit I] have the same meaning as described, and wherein A and B eachindependently represent a member selected from the group consisting ofOH, -0M, -NH

I 1 Nu, oNHi These water-soluble interpolymers may be easily derivedfrom the above-described interpolymers by forming derivatives of theanhydride portion of the polymer, by known hydrolyzing reaction thereofwith water, and/or reactions involving primary and secondary alcohols,primary and secondary amines or alkali basic media to fon'n salts,partial ester-salts, or partial amide-salts and the like.

Among the more preferred reactants that may be mentioned are water,ammonia, alkali solutions, such as sodium hydroxide, potassium hydroxideor ammonium hydroxide, etc.; methylamine, piperidine, morpholine,diethanolamine, triethanolamine, etc.; alcohols, such as methanol,ethanol, propanol, and the like; phenols, naphthols, etc.

The invention provides novel interpolymers particularly useful inthickened aqueous systems, i.e., in a composition of matter comprisingan aqueous system having therein a thickening amount of the watersoluble derivatives of the instant anhydride interpolymers, definedabove. Such systems include, for example, water itself, aqueous-alkalinemixtures, aqueous-alcohol mixtures, aqueous-acid systems, aqueous ionicsalt mixtures, polymer latices, and the like. Examples of the aqueousionic salt acid or alkali systems which can be thickened in accordancewith present invention include solutions of diammonium phosphate,tetrapotassium pyrophosphate, ammonium hydroxide, sodium hydroxide,sodium bromate, hydrochloric acid, and the like.

The amount of water present in the above-mentioned aqueous systems is inno way critical, as the thickeners employed can be utilized to thickencompositions wherein water is present in only a minor amount to anaqueous system, per se. The amount of water present in the aqueoussystem, therefore, is merely dependent on the use for which thethickened system is intended. In general, however, it is preferred toutilize aqueous solutions containing 1 to 60% ionic material.

Furthermore, the amount of thickener to be employed in the aqueouscompositions will vary according to the desired result, the systememployed, and as a practical matter, the general economicconsiderations. In general, however, a range of from about 0.1 percentto about 15 percent by weight of the total aqueous composition isemployed, although greater or lesser amounts can be advantageouslyemployed when desired.

The use of the instant thickeners in the above aqueous systems is indeedunique. For example, in many ionic solutions using standard thickeners,the viscosity decreases as the ionic content increases. Hence, it wasunexpected that the viscosity increased with ionic content when usingthe novel subject thickeners.

The following examples are illustrative of the present invention and arenot to be regarded as limitative. It is to be understood that all parts,percentages and proportions referred to herein and in the appendedclaims are by weight unless otherwise indicated. The viscosities listedin the following examples were obtained with a Brookfield rotationviscometer and the value expressed in centipoises.

EXAMPLE I A 5 mole percent hydrogenated tallow amide of ethylene maleicanhydride copolymer was prepared by dissolving 12.6 g. (0.1 mole) ofethylene maleic anhydride copolymer (specific viscosity 1 percent inacetone 0.58) in 300 ml. of C. P. Acetone in a 500 ml. reaction flaskequipped with stirrer, reflux condenser and thermometer. 1.5 g. (0.005moles) of hydrogenated tallow fatty amines, comprising a mixture of 25percent of hexadecyl amine, 70 percent of octadecyl amine and percent ofoctadecadienylamine previously dissolved in 10 ml. of C. P. methyl ethylketone, was then added. The solution was stirred for hours at 27 to 28C. and then poured into 600 ml. of normal heptane. The liquid wasdecanted from the polymer solids which were then dried in a high vacuumoven to a constant weight of 13.7 g.

EXAMPLE II A 4 mole percent hydrogenated tallow amide of styrene maleicanhydride copolymer was prepared by dissolving 10.1 g. (0.05 moles) ofstyrene maleic anhydride copolymer (specific viscosity 1 percent acetone1.9) in 300 ml. of C. P. acetone in a 500 ml.

' reaction flask equipped with stirrer, reflux condenser andthermometer. 0.6 g. (0.002 moles) hydrogenated tallow fatty amines ofExample I dissolved in 10.0 ml. of C. P. methyl ethyl ketone was thenadded thereto. The solution was stirred for 19 hours at approximately 26to 28 C. and then poured into 1 l. of normal heptane. The liquid wasdecanted from the polymer solids which were dried in a high vacuum ovento a constant weight of9.l g.

EXAMPLE III An 8 mole percent cetyl alcohol ester of styrene maleicanhydride copolymer was prepared by dissolving 10.1 g. (0.05 moles)styrene maleic anhydride copolymer of Example II in 300 ml. of C. P.acetone in a 500 ml. reaction flask equipped with stirrer, refluxcondenser and thermometer. 1.0 g. (0.004 moles) cetyl alcohol dissolvedin 10.0 ml. C. P. methyl ethyl ketone was then added to the above. Thesolution was stirred for 19 hours at a temperature from about 26 to 28C. and then poured into 600 ml. normal heptane. The liquid was decantedfrom the polymer solids which were then dried in a high vacuum oven to aconstant weight of 9.1 g.

EXAMPLE IV A solution comprising:

G. lnterpolymer of Example I 2.0 Distilled water 46.0 Ammonia solution,28.9% 52.0

was prepared. The polymer solution exhibited a Brookfield viscosity of41,600 CPS at C. using a No. 7 spindle and 10 RPM.

For comparison, a control solution was prepared substituting the parentethylene maleic anhydride copolymer for the novel interpolymer of theinstant invention. The resultant solution showed a Brookfield viscosityof 48 CPS.

EXAMPLE V A solution comprising:

G. lnterpolymer of Example 11 5.0 Distilled water 44.9 Ammonia solution,29.9% 50.1

was prepared. The polymer solution exhibited a Brookfield viscosity of16,080 CPS at 25 C. using a No. 7 spindle and 10 RPM.

EXAMPLE VI A solution comprising:

6. lnterpolymer of Example III 2.5 Distilled water 21.5 Ammoniasolution, 28.9% 26.0

was prepared. The polymer solution exhibited a Brookfield viscosity of2,000 CPS at 25 C. using a No. 7 spindle and 10 RPM.

A comparison solution was prepared using the parent styrene maleicanhydride copolymer, which solution showed a Brookfield viscosity of 560CPS at 25 C. using a No. 5 spindle and 10 RPM.

EXAMPLE VII A solution comprising:

G. lnterpolymer of Example I 1.0 Distilled water 46.5 Diammoniumphosphate 2.5

was prepared. The polymer solution exhibited a Brookfield viscosity of2,000 CPS at 25 C. using a No. 6 spindle and 10 RPM.

A comparison solution was prepared using the parent ethylene maleicanhydride copolymer in lieu of the interpolymer of the instantinvention. This comparison solution showed a Brookfield viscosity of 20CPS.

EXAMPLE VIII A solution comprising:

G. lnterpolymer of Example II 1.0 Distilled water 46.5 Diammoniumphosphate 2.5

EXAMPLE IX A solution comprising:

G. lnterpolymer of Example 1 2.0 Distilled water 45.5 Sodium carbonate2.5

was prepared. The polymer solution showed a Brookfield viscosity of 5600CPS using a No. 7 spindle at 10 RPM.

A comparison solution was prepared using the parent ethylene maleicanhydride copolymer in lieu of the novel interpolymer of the instantinvention. This comparison solution showed a Brookfield viscosity of 40CPS using a No. 3 spindle at 10 RPM.

EXAMPLE X A solution comprising:

G. lnterpolymer of Example 11 1.0 Distilled water 46.5 Tetrapotassiumpyrophosphate 2.5

was prepared. The polymer solution showed a Brookfield viscosity of9,000 CPS using a No. 6 spindle at 10 RPM.

EXAMPLE XI A mole percent hydrogenated tallow amide of ethylene maleicanhydride copolymer was prepared by heating 50.0 g. of 5 mole percenthydrogenated tallow amide of ethylene maleic anhydride copolymer ofExample I for several hours at 180 C.

EXAMPLE XII A solution comprising:

. G. interpolymer of Example XI 5.0 Distilled water 43.0 Ammoniasolution, 28.9% 52.0

was prepared. The polymer solution was compared with a control inwhichthe parent ethylene maleic anhydride copolymer was used in lieu ofthe novel interpolymer of the instant invention. The compositioncontaining the novel interpolymer of the instant invention was found tobe considerably thicker than the control.

As will be readily appreciated, the foregoing examples clearly delineatethe novelty of the instant invention, and further exemplify the factthat the novel interpolymers of said invention are particularly wellsuited for use as thickening agents in connection with aqueous systemsof high ionic strength.

Various modifications and variations of this invention will be obviousto a worker skilled in the art and it is understood that suchmodifications and variations are to be included within the purview ofthis application and the spirit and scope of the appended claims.

What is claimed is:

I. An uncrosslinked, water-soluble interpolymer wherein Y represents and-0 --R and wherein Y represents -OH and Y and R together represent asingle bond of an imide ring, X represents either or O, R represents thesame or different hydrocarbon radicals containing from about C to aboutC carbon atoms selected from the group consisting of normal chain alkyl,branched chain alkyl, cycloalkyl and alkylaryl radicals, R represents Hor the same or different hydrocarbon radicals containing from about C toabout C carbon atoms selected from the group consisting of normal chainalkyl, branched chain alkyl,

cycloalkyl, and alkylaryl radicals wherein the sum total of carbon atomsrepresented by R and R is not greater than C and when X is -O- or animide nitrogen, R does not exist; R represents either hydrogen, methyl,ethyl or phenyl and R represents either hydrogen or methyl wherein UnitI represents about 94 to 995 mole percent and Unit ll represents fromabout 6 to about 0.5 mole percent of the interpolymer, said interpolymerhaving a specific viscosity range (1 percent in acetone) of from 0.2 toabout 20.0.

2. The interpolymer according to claim 1 wherein R represents ahydrocarbon radical having from six to 20 carbon atoms.

3. The interpolymer according to claim 1 wherein R is an alkyl radicalhaving from six to 20 carbon atoms.

4. The interpolymer according to claim 1 wherein R represents a methylradical.

5. The interpolymer according to claim 1 wherein X represents nitrogen.

6. The interpolymer according to claim 1 wherein X represents oxygen.

7. The interpolymer according to claim 1 wherein R is an alkyl radicalhaving 16 carbon atoms.

2. The interpolymer according to claim 1 wherein R1 represents ahydrocarbon radical having from six to 20 carbon atoms.
 3. Theinterpolymer according to claim 1 wherein R1 is an alkyl radical havingfrom six to 20 carbon atoms.
 4. The interpolymer according to claim 1wherein R3 represents a methyl radical.
 5. The interpolymer according toclaim 1 wherein X represents nitrogen.
 6. The interpolymer according toclaim 1 wherein X represents oxygen.
 7. The interpolymer according toclaim 1 wherein R1 is an alkyl radical having 16 carbon atoms.